This invention relates to parts that require surface roughness such as metal components used in turbine engines and more specifically to enhancing the heat transfer properties of various surfaces of the parts.
Various techniques have been devised to maintain the temperature of turbine components below critical levels. For example, coolant air from the engine compressor is often directed through the component, along one or more component surfaces. Such flow is understood in the art as backside air flow, where coolant air is directed at a surface of an engine component that is not directly exposed to high temperature gases from combustion. In combination with backside air flow, projections from the surface of the component have been used to enhance heat transfer. These projections or bumps increase the surface area of a part and thus increase heat transfer with the use of a coolant medium that is passed along the surface. The projections are formed by one of several techniques including wire spraying and casting.